SURFACE AND GROUNDWATER NEXUS: MANAGEMENT OPTION IN IRRIGATED AREAS OF LOWER BARI DOAB CANAL USING MODELING APPROACH

Lower Bari Doab Canal is the oldest irrigation system, however LBDC inequitably distribute the water from head to tail end. Spatial climate variability across the command area of LBDC has impact on reallocation of canal water supply and usage of irrigated water from head end to the tail end. The irrigation demand is increased with the increasing of cropping intensity due to increase of population, hence the surface water supply and rainfall do not fulfilled the crop water requirement then farmer abstracted more groundwater for fulfilled these requirement. At the tail end of LBDC, farmer extracted more water is causing groundwater mining due to lack of technical knowledge related to the management of groundwater. Now to management of this problem using simulation water balance approached from the data 2017- 2018 year. The water balance result show that total inflow in to system is 8197.13MCM from considering the parameter of recharge is 4006.278 MCM, supply from the canal is 4190.85 MCM but the total annual outflow is 18487.872 MCM from considering the parameter of evapotranspiration and groundwater abstraction. The change in water storage is (-10290.74MCM). The future scenarios result show that Scenario1: Due to climate change and uneven rainfall my cause to the now condition of groundwater and canal is not fulfill the crop water requirement. Scenario 2: Due to increase of groundwater the water table abstraction more decline at the end of the tail as compared to the head, the water abstraction falling at the 2.06m as compared to the head end 1.2m from the year 2017-2018 then it also effect on the water balance (-1131.31 MCM) to (- 12812.44). The result suggested that to manage the canal water supply, to build the storage system from saving the water at head end then to easily provide this to tail end and to avoid those crops which required more irrigation water and to use the artificial technique for the recharge of groundwater.